Grain yield improvements by conventional breeding have nearly reached a plateau in maize. It is natural then to explore some alternative, non-conventional approaches that could be employed to obtain further yield increases. Since the harvest index in maize has remained essentially unchanged during selection for grain yield over the last hundred or so years, the yield improvements have been realized from the increased total biomass production per unit land area (Sinclair, et al., (1998) Crop Science 38:638-643; Duvick, et al., (1999) Crop Science 39:1622-1630 and Tollenaar, et al., (1999) Crop Science 39:1597-1604). This increased total biomass has been achieved by increasing planting density, which has led to adaptive phenotypic alterations, such as a reduction in leaf angle and tassel size, the former to reduce shading of lower leaves and the latter perhaps to increase harvest index (Duvick, et al., (1999) Crop Science 39:1622-1630).
The ZM-ZFP1 is a maize zinc finger protein gene. Over-expression of Zm-ZFP1 using a seed preferred promoter has been shown to be able to enhance plant growth, increase kernel number and total kernel weight per plant. The overexpression of Zm-ZFP1 would lead to increased grain yield in maize and other crop species. Zm-ZFP1 is homologous to rice Os01g0839100 and contains two Zinc finger bonding motifs that are highly conserved.
Experimental data shows that the expressed ZM-ZFP1 gene confers a strong positive effect on yield traits in maize, including enhanced growth, increased kernel number and increased grain yield.
Methods and compositions are needed in the art which can employ such sequences to modulate plant tissue growth and improve yield in plants.